New battery from a variety of nanoelements

For a variety of reasons, new ways of storing energy are constantly being sought, while the existing ones are improving. We are increasingly using wireless devices. People hopefully look at electric cars. Tesla Motors has clearly shown that electric cars can be not just a means of transportation for particularly zealous fighters for the environment, but also very sports cars. There is no need to switch speeds to set or reset the speed, and any driver very quickly gets used to this “endless” first gear.

News about the next breakthrough in the structure of batteries, which will change the entire industry, appear at least once a month. Usually, scientists either change the design or try new materials. In the new study, it was possible to restructure materials into a nano-battery, and then merge their group into a battery.

Any battery consists of two electrodes, between which a potential difference is created. Electrodes based on nanostructures have a number of useful qualities: this is a large surface area and a short ion transport time, which allows you to store more energy and improve the battery life time, that is, it can hold a charge longer and undergo more charge-discharge cycles. Another room for improvement is left by the 3D organization of these structures.

In the past, researchers developed 3D batteries by placing two electrodes in aluminum oxide nanopores, and ultrathin insulation material was used to separate them. Although the resulting system had improved energy conservation density indicators, charge retention is limited to insulators, and requires a circuit to be complicated for current to flow between them. Simply put, it is difficult to retain the positive features of 3D nanostructures due to the spatial limitations of the material.
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Usually electrolyte is used in batteries, but with its use nano-batteries showed low rates of stored charge. When combining such batteries in 3D structures, differences in concentrations led to differences in current density. It was possible to circumvent these limitations by combining both solutions.

The new battery consists of parallel located nanoelements. Each of the tubes contains electrodes and a liquid electrolyte located in the pores of aluminum oxide, and the current is collected by nanostructures from ruthenium (the outer surface of the tube) and vanadium oxide V ₂ O ₅ (the inner surface). To form the cathode and the anode, the nanopores are covered, respectively, with either a layer of vanadium oxide or its chemically modified form.

The performance of both the individual electrodes (half of the cell) and the complete structure of the nanoaccumulator, containing both electrodes and other elements, was determined. Both configurations have excellent energy and battery life savings. Each gram of the resulting structure can save 80 mAh, which is slightly lower than existing lithium batteries, and after 1000 charge-discharge cycles, the stored charge drops by only 20 percent or even less. If we compare it with previous samples using nanopores, the stored charge has tripled, and the cyclic durability has increased by an order of magnitude.

These qualities, according to researchers, are caused by a coaxial tubular structure. Its properties were detected by comparing the stored charge of the nanotube configurations of vanadium oxide and ruthenium and the planar arrangement of silver and vanadium oxide. In nanotubes, the characteristics of the stored charge were significantly higher.

Thus, it was shown that with proper scaling, nanostructures can help to improve rechargeable batteries. Perhaps in the future, this version of building a battery will become a real prototype for working in mobile phones, tablet computers and other portable devices.

Based on Ars Technica . DOI: 10.1038 / NNANO.2014.247 .